There are three general types of chocolate: dark (sweet) chocolate (as defined in CFR 21: 163.123), milk chocolate (CFR 21: 163.130) and white chocolate (CFR 21: 163.124), all of which are derived from cacao beans, particularly compositions derived from cacao beans, such as cocoa liquor, cocoa powder, and/or cocoa butter. Traditional dark chocolate may be defined as a product, which is obtained from cocoa liquor consisting of cocoa liquor containing about 54% of cocoa butter, sucrose and additional cocoa buffer. Milk chocolate contains milk in addition to the dry matter. White chocolate also contains milk but lacks cocoa solids.
All of these chocolates may be combined with filling ingredients such as hazel nuts, crisped rice, desiccated fruits or the like. From a physical point of view, a chocolate may be assimilated with a practically anhydrous dispersion of very fine nonfatty particles (sucrose, lactose, proteins, minerals and the like) in a solidified fatty phase of triglycerides. The triglycerides may be solely derived from cocoa liquor in the case of a dark chocolate, but also are derived from milk fat and cocoa butter in the case of milk or white chocolate.
The preparation of chocolate involves four stages: mixing/kneading, refining, conching, and tempering. In the first stage the ingredients are mixed together in a kneading process that also involves refining, or grinding, for example, on a multiple roll refiner to provide a smooth fluid paste. The ingredients may be added sequentially, and in particular the cocoa butter may be added step-wise to control the viscosity of the composition. The sugar may also be pre-ground to a smaller particle size to reduce the length of time required in the kneading and refining of the chocolate mixture. The paste resulting from kneading should have a specific texture that is appropriate for the subsequent refining operation. It is possible to control the texture by the choice of the particle size of the sugar, fat content, and/or addition of emulsifiers.
After kneading and refining, most chocolate is subjected to the process of conching when the chocolate mixture is mechanically worked to give the chocolate a fuller and more homogeneous flavor and improved rheological characteristics. This is typically done at increased temperatures, ranging from 75° C. to 80° C. for dark chocolate, and about 65° C. for white and milk chocolates. Other ingredients such as flavors, for example, vanilla, and extra cocoa butter may be added at this stage if desired. A frequently added additional ingredient is lecithin or other emulsifiers, which improve the flow properties of the chocolate and thereby enables the amount of cocoa butter to be reduced.
The third stage of the chocolate preparation is called tempering, in which the liquid chocolate composition is cooled to a temperature below its solidification temperature and then reheated in order to form the proper fat crystal structure to facilitate the rapid crystallization of its fat content on cooling. The final appearance of the chocolate, its texture and keeping properties depend upon correct tempering stage conditions. After tempering, and in the fourth stage of molding, the chocolate may finally be cast into molds to set or may be used in an enrobing process to produce chocolate-coated confectionery, etc.
In another production technique known as the crumb technique, liquid milk or concentrated milk products are mixed with sugar and a chocolate composition, and subsequently heated to boiling point under vacuum. This mixture is worked with or without cocoa liquor before drying under high vacuum in order to obtain a powder containing less than 1% water. This process makes it possible to obtain a milk chocolate having organoleptic properties, which are very different from those obtained with the conventional method. The product obtained from the crumb technique may be further refined by milling to a product with a homogeneous particle size. The product may also undergo many of the physical treatment processes common with other non-crumb chocolates.
With each manufacturing technique, and at all stages of each technique, it is important to control the viscosity of the chocolate composition in order to achieve desired texture characteristics of the finished product and ensure proper workability of the composition. Viscosity is controlled by the amount of liquid added; as for example, in the form of cocoa butter and/or milk in the composition; and it is important to control its addition in order to maintain proper viscosity ranges and ensure proper quality of the final composition.
Chocolate confectionary products have traditionally derived their sweetness from sucrose (table sugar). Its organoleptic and technological properties render it particularly suitable for this type of confectionery product. Sucrose is a disaccharide comprised of a glucose and fructose moieties, and is present in processed foods in significant amounts. Sucrose may be harmful to humans when consumed in large quantities, affecting dental health by contributing to cavities in teeth (cariogenic), as well as contributing to obesity and diabetic conditions. Because of its abundance in processed foods, many consumers monitor their sucrose intake, and there is also accordingly a high consumer demand for sugar-free foods.
Other sweeteners have therefore been proposed and some have been used to provide dietary type chocolate for diabetics and slimmers. One class of replacement sweetener for sucrose in chocolate is the so-called sugar alcohols, or polyols, in particular sorbitol, maltitol and mixtures of sugar alcohols typically known as hydrogenated starch hydrolysates. Sugar alcohol sweeteners, besides contributing fewer calories to the chocolate than the equivalent quantity of sucrose are also far less cariogenic. Polyols are also slowly metabolized and they do not cause a sharp rise in the level of blood glucose following their consumption. Consequently, they are often recommended in the diet for diabetics. Furthermore, their calorific value is estimated at a mean value of 2.4 kcal/g (10.0 KJ/g), that is to say about 60% of that for sugar.
However, there are technological manufacturing imperatives, including in particular, the rheological properties, which are necessary in order to perform the refining, conching and molding operations under satisfactory conditions, which prevent widespread use of effective compositions containing polyols as a substitute for sucrose in chocolate.
This is true particularly for refining, which is a stage in which the paste must be sufficiently cohesive in order to be properly suitable for grinding in the rollers of the refining device. A paste, which is too dry, would render the rolling impossible. Polyols, by virtue of their hygroscopicity, tend to increase this viscosity of the paste. It should be noted that the addition of an emulsifier such as lecithin prior to conching with the intent to reduce the viscosity of the chocolate paste, can compensate only to a certain degree. Indeed, excess lecithin in a chocolate mix typically leads to the formation of an undesirable stable water-in-oil emulsion. A too stable emulsion prevents the evaporation of water and volatile compounds which is sought during conching. Worse still, formation of a too stable emulsion also may lead to an effect which is the reverse of that sought, namely an increase in the yield point of the chocolate paste.
Moreover, some polyols are highly hygroscopic which poses storage problems during the manufacturing process. Thus, when polyols are included in a chocolate recipe, manufacturers typically use conditioned atmospheres with controlled humidity levels in order to avoid water being taken up. This phenomenon is observed for sorbitol in particular.
Still with respect to these hygroscopicity problems, the brittleness and the morphology of the crystalline powders of some polyols, such as sorbitol and hydrogenated isomaltulose, cause, during refining, the formation of particles having a specific surface area which is greater than that of sugar. This renders the worked paste more hygroscopic and therefore more viscous, and requires the use of a higher amount of fatty substances in order to improve the Theological behavior of this paste. Moreover, the temperature increases which occur directly or indirectly during the grinding, kneading, refining, or conching operations render the polyols more unstable for a number of reasons.
Firstly, the hygroscopicity of the polyols increases. In the specific case of sorbitol, the critical relative humidity, the relative humidity which should not be exceeded in the manufacturing environment, thereby drops from 73% to 62% when the temperature is increased from 20° C. to 40° C. Secondly, the temperature increases may result in a disorganization of the crystalline states, by releasing the water of crystallization when the relative humidity is low in the case of polyols of hydrated crystalline form (hydrogenated isomaltulose, lactitol monohydrate and the like), or by melting of the crystals in the case of polyols having a low melting point (xylitol, sorbitol and the like). This melting or disorganization of the polyol crystals results in a transition to a very hygroscopic amorphous state in the later stages of the preparation of the chocolate composition. It should be noted that melting of the polyol (which may occur) occurs at a later stage in the manufacturing process and is an undesirable side-effect as the chocolate compositions are largely unworkable as a result of the increased viscosity.
European Patent Application No. 0317917, for its part, relates to a process for manufacturing sugar-free and noncariogenic milk chocolate using the so-called “crumb” technique. The sugar substitutes used in this process are maltitol, lactitol or hydrogenated isomaltulose (equimolar mixture of 1,6-glucopyranosylmannitol and 1,6-glucopyranosylsorbitol, which is marketed under the registered trade mark ISOMALT). The chocolates manufactured according to this process have a fat content which is not less than 35% by weight.
U.S. Pat. No. 5,962,063 to Siukola, et al. discloses a process for preparation of chocolate crumb using sugar alcohols. The process focuses on adding the polyols in a crystalline state in portioned amounts, controlling the temperature during the process so that not all of the bulk sweetener (polyol) was dissolved. It was found in Siukola that if all of the sweetener was dissolved and/or melted during the procedure, the chocolate manufacturing method was ineffectual.
Japanese Patent Application No. 60/232058 describes a chocolate in which sugar is replaced with a mixture of maltitol powder and lactose or maltose or mannitol or a mixture of these. The fat content of some of the chocolates, whose preparation is described in the examples and in the control tests, is of the order of 26.5% by weight, but it is explicitly indicated in that patent application that the chocolate, whose sweetening mass consists solely of maltitol (control 2), is of poor quality, namely that it is granular, that it has a sweet taste which is unsatisfactory and that it has a sandy feel on the tongue. Furthermore, it is also stressed that its production process is very difficult to implement. The polyol used to prepare the chocolate product consists of a maltitol syrup powder. The described maltitol-containing chocolate is used, moreover, as negative control which is intended to demonstrate the advantages of the invention which is claimed in that application and which, precisely, provides for the use of the mixture of maltitol and at least one other sugar such as maltose, lactose or mannitol, in order to overcome the disadvantages of a low-fat chocolate whose sweetening mass would consist solely of a polyol such as maltitol. The reading of that document could only have convinced a person of ordinary skill in the art not to use maltitol as sweetening mass for preparing a low-fat polyol-containing chocolate.
U.S. Pat. No. 5,360,621 to Mentink et al. also discloses using maltitol as a sugar substitute in a chocolate composition. The disclosure of Mentink provides for using a maltitol composition of extremely high purity with a total fat content of less than 32% by weight in order to provide for a chocolate composition with suitable viscosity and flowable characteristics.
While there are drawbacks to using polyols in crystalline structure in a chocolate composition, the use of a polyol in a fluid state has also been thought to have numerous adverse affects on the rheological properties of the chocolate preventing its implementation. Primarily, a chocolate composition comprising a polyol in a fluid state would increase its viscosity to an unworkable state, which adversely affects the texture and taste of the finished product. Furthermore, a chocolate composition with a high moisture content resulting from using a liquid polyol would have increased susceptibility to microgrowth of bacteria and other undesirable organisms.
While the dissolution and/or melting of the sweetener in a chocolate composition is often unavoidable, it has been contemplated to prevent its occurrence in most instances in the art; see, for example, U.S. Pat. No. 5,962,063 to Siukola. It is desirable therefore to provide a sugar-free sugar substitute which may be introduced into a chocolate composition in an amorphous state and a chocolate mixture suitable to accommodate use of the amorphous sweetening additive.
Liquid polyols have however, been used in chocolate compositions, but not as a replacement for sugar. U.S. Pat. No. 4,664,927 to Finkel, for example, discloses the addition of a liquid polyol to a chocolate composition in order to adjust the Theological properties of the chocolate. The liquid polyol is added in addition to sucrose or sweetener already present in the chocolate composition and is added only after tempering of the chocolate composition in order to create a chocolate composition which is substantially non-flowable at temperatures above its normal melting point.
U.S. Pat. No. 6,488,979 to Davila et al. also discloses the addition of liquid polyols such as glycerine, sorbitol, and mannitol in order to create a chocolate composition which is resistant to melting. Similarly, the '979 Davila patent discloses that the liquid polyol should be added in addition to sucrose or the sweetening agent of the chocolate composition. Neither the '927 Finkel reference or the '979 Davila reference disclose the use of a liquid sweetening agent but rather use a liquid polyol in order to adjust the viscosity and create a chocolate composition with increased resistance to melting after its manufacture.
In each case, the attempt to use a polyol as a sweetener or replacement for sugar has focused on attempts to use it in its crystalline state as flowable liquid polyols are believed to not be suitable for use in chocolate compositions as the sweetening agent. However, many of the problems associated with using polyols as a substitute for sucrose have not been overcome. There is a need therefore to develop a method of making a chocolate confection or composition, for example a sugar-free chocolate confection, using an amorphous sweetening composition. It is further desirable to provide a method of making chocolate that effectively uses an amorphous polyol as the sweetener composition. It is further desirable to develop a method of making a sugar-free chocolate confection without the deleterious side-effects of using a polyol as a substitute for sucrose.